1. Field of the Invention:
This invention relates to a center locking device of the intermediary plate type for both locking and burglarproofing purposes to be provided inside a cap nut for a disc wheel of motor vehicle.
2. Prior Art:
In the conventional disc wheel for a motor vehicle, a flange with a threaded tube is fastened to a hub of an axle. A center hole of a disc is fitted on the threaded tube. A cap nut is screwed on the tube and thus the disc is fastened to the axle. As the disc is generally made of aluminum and has no clamp nut at a boss, it provides for a good appearance. However, since it has no center locking means, the cap nut is liable to become loose when a driver applies the brakes sharply. Also, since there is no locking device for the cap nut, the cap nut can be removed easily and accordingly disc wheels are apt to be stolen.